"more suffer to the oppressor, that's not fair. The attack rates must be counter by the same rates."
They learned this from Judaism:
https://en.wikipedia.org/wiki/Eye_for_an_eye#In_Torah_LawIn the Hebrew Law, the "eye for eye" was to restrict compensation to the value of the loss. Thus, it might be better read 'only one eye for one eye'.[1] The idiomatic biblical phrase "an eye for an eye" in Exodus and Leviticus (עין תחת עין, ayin tachat ayin) literally means 'an eye under/(in place of) an eye' while a slightly different phrase (עַיִן בְּעַיִן שֵׁן בְּשֵׁן, literally "eye for an eye; tooth for a tooth") is used in another passage (Deuteronomy) in the context of possible reciprocal court sentences for failed false witnesses.[8][9][10] The passage in Leviticus states, "And a man who injures his countryman – as he has done, so it shall be done to him [namely,] fracture under/for fracture, eye under/for eye, tooth under/for tooth. Just as another person has received injury from him, so it will be given to him." (Lev. 24:19–21).[8]
This is a materialistic trading calculation. Yet ethical trading must be based on mutual consent. Once one side initiates violence, the two sides are not in a trading relationship any more, therefore to nevertheless continue with trading calculations is to ignore the ethical prerequisites of trade.
In terms of fairness, the only people who deserve to be treated fairly are those who treat others fairly. Oppressors by definition do not treat others fairly. To continue to treat oppressors "fairly" is thus in fact to be unfair to everyone else.
"My answer is we need them to stop their action"
This is a practical duty, which I also acknowledge. But it is separate from the issue of what they deserve. If someone initiated violence in the past but then became paralyzed (thus are guaranteed to never initiate violence again), they still deserve to be punished for the violence they initiated in the past no less than someone else who initiated similar violence but who did not become paralyzed.